Holder for erasers



W. H. FROST HOLDER FOR ERASERS April 30, 1929.

Filed Oct. 10, 1925 Patented A r. 30, 1929.

UNITEDSTATES WILLIAM H. FROST, or SAN JOSE,;QALIFOR1\TIA.

HOLDER FOR ERASERS.

Application filed October 10, 1925Q Serial No. 61,817.

My invention relates to holders for erasers and the like and has for itsobject to provide an inexpensive and ellicient holder of this kindparticularly adapted to hold a typewriter eraser. It is also an objectof my invention to provide a device of this character in the form of anattachment adapted to be applied to the frame of a typewriter and tosupport an eraser in an accessible and convenient position outof the wayof the person using thetypewriter, and which will automatically returnthe eraser to this position after each use of the latter.

To these ends I have provided a novel holder for erasers and the likehaving the peculiar featuresof construction and mode of operation setforth in the following description, the novel features of the inventionbeing particularly pointed out and defined in the claim at the closethereof. 7

In the accompanying drawings: v

Figure 1 is a front elevation on a scale about twice full size of aneraser holder constructed in accordance with my invention.

Figure 2 is a central vertical sectional view of the holder shown inFigure 1.

Figure 3 is a detail hereinafter described. My new holder for erasers,as herein shown, comprises a frame 1 made from sheet metal andconstructed with a chamber 2 within which is housed a pulley 3, and alsoformed upon its front side with a pocket 4 within which is housed aneraser 5 of ordinary construction; The front wall of the frame 1 isformed with a hole through it which is bordered by an eyelet 6, saidhole affording a passage by which chamber 2 is connected with theinterior of the pocket 1 at the middle of the latter.

The pulley 3 is rotatably mounted upon a stud 7 rigidly fixed to thefront wall of frame 1 and said pulley has fastened to it the outer endof. a coiled spring 8 whose inner end is fastened to the post 7 A cordor chain 9 is wound onto the pulley 3 and has one end thereof fastenedto the pulley while the opposite end portion extends through theeyeleted hole 6, the usual eyeleted hole 10 of the eraser 5, and througha washer 11, with the extremity thereof, outside washer 11, formed intoa knot 12. It will thus be clear that with the spring 8 under tensionthe cord 9 will be kept wound up on the pulley 3 and the draft on thecord will serve to hold the eraser 5 Within its pocket 4. s

The wall of the pockete: is cut away, or recessed, as at 13, to leaveuncovered a portion of the eraser so that said exposed por-' tion can berasped between the thumb and forefinger when it 1s desired to remove anduse the eraser,

l Vithin the pulley 3 is fixed a ring 1 4: whose inner periphery isformed with a pocket at opposite sides of which are shoulders15 and 16,and with a cam surface'17 which includes about one-fourth of said innerperiphery and terminates at the shoulder 15, the remaining three-fourthsof said inner periphcry being concentric withthe axis of the pulley andterminating at the shoulder 16. Within this ring 14L are arranged threeclutch balls 18 which are also housed in part within holes 19 providedin a circular plate or head 20 fixed rigidly to one end of post 7 whoseopposite end, as stated above, is fixed rigidly to the frame 1. At oneside thereof each hole 19 is formed with an abutment surface 21 that isapproximately radially disposed and at the opposite side with a camsurface 22. The spring 8, Fig. 2, normally urges the pulley 3 and ring20 in the direction of the arrow, Fig. 3', and normally one of the balls18 will occupy the outer portion of the hole 19 below the axis of thepulley and the .pocket formed by the shoulders 15 and 16, with theshoulder 21 opposing movement of the ball by the shoulder 16 on thepulley. Consequently when the eraser has been removed from its pocketand the cord unwound from the pulley, the spring is prevented frompulling upon or winding up the cord, by the engagement of the shoulders16 and 21 with one of the balls. When it is desired to cause the springto wind up the cord and return the eraser to its pocket 4, this iseffected by giving a quick jerk to the cord and releasing the samewhereupon the spring will wind up the cord fully and pull the eraserback into its pocket. 7

When the cord is jerked quickly as described, the pull upon the cordrotates the pulley clockwise a short distance during which movement theshoulder 15 shoves the ball along the cam surface 22 toward the axis ofthe pulley so that it occupies a position at the inner end of its hole19. Now, while the spring is rapidly rotating the pulley in acontra-clockwise direction and winding up the cord the pocket -16 iscarried past the ball so rapidly that the pocket 15- 16 does not occupya position below the ball long enough to permit gravity to overcome theinertia of the ball and move it downwardly into said pocket. It will,therefore, be clear that while the clutch mechanism describedautomatically locks the pulley with the cord unwound therefrom while theeraser is in use, said mechanism may be caused to operate automaticallyto rewind the cord upon the pulley and thereby return the eraser to itspocket 4, by exerting a quick jerk upon the cord. I would have itunderstood, however, that in some forms of my inven tion I do not employthe clutch mechanism. including the balls 18, head 20 and ring 1 1,

In Figure 2 I have shown the frame 1 as provided upon the rear sidethereof with means for attaching said frame to the frame A of atypewriter, or to any other suitable supporting fixture. This means, asshown, may consist of a clamp 22 secured by rivets to frame 1 having ajaw 23 to engage one side of the fixture A and a clamping screw' 24 toengage the opposite side thereof.

What I claim is:

A holder attachment for erasers comprising a sheet metal frame formedwith a pul ley chamber, and with a passage leading from said chamberthrough one wall of said frame to the exterior of the latter; a pulleyrotatably mounted within said chamber; a spring for rotating said pulleyin one direction; a cord wound on said pulley by said spring and havingone, end thereof connected with the pulley, said cord extending fromsaid pulley throngh said passage; an eraser to which the outer end ofsaid cord is connected; a cupshaped pocket upon the front side of theframe within which said eraser is held by the cord, said eupshapodpocket having a back wall formed with a linger notch and including anoutstandin segmental wall partly surrounding the eraser so that only arelatively small and limited marginal portion of the latter is leftexposed to permit the eraser to be grasped by the fingers and means onthe rear side of said frame for separably fastening said frame to asiimport.

wILLfA rr. rnosr.

